Effect of residue and rates and sources of phosphorus application on growth, yield and economics of wheat (Triticum aestivum)

Field experiments were conducted during 2001-02 and 2003-04 to study the effect of crop residue incorporation on the relative efficiency of diammonium phosphate and Mussoorie rock phosphate. The results indicated that phosphorus application significantly increased plant height from 78-81 to 81-84 cm, number of grains from 56-58 to 57-65, 1 000 grain weight from 33-34 to 34-39 g, grain yield 4.1-4.5 to 4.4-6.2 tonnes/ha, gross profit from Rs 28 014-31 657 to Rs 29 528-43 121/ha and net profit from Rs 7 086-10 729 to Rs 8 603-20 908/ha. The response was limited to 40 kg P₂O₅ either as diammonium phosphate or Mussoorie rock phosphate, however the economic optimum dose of Mussoorie rock phosphate was 53-79% higher than that of diammonium phosphate but produced almost similar yield (4.6-6.1 tonnes/ha) at their economic optimum dose. Agronomic efficiency and response and economic returns at economic optimum dose was higher with diammonium phosphate than with Mussoorie rock phosphate. Residue incorporation had no significant effect on growth, yield attributes, yields and gross and net returns of wheat but significantly increased the efficiency of both diammonium phosphate and Mussoorie rock phosphate. Thus, a combination of Mussoorie rock phosphate + phosphorus-solubilizing bacteria + crop residue incorporation hold a great promise as a P fertilizer in wheat for its increased productivity under north Indian condition.